Out of Plane Approach for Interscalene

Studies have proven that there is 100% blockade of the phrenic nerve with the in-plane
approach to the interscalene brachial plexus block. The patient population with pulmonary
comorbidities with poor reserve cannot afford to have a further deterioration of their
pulmonary status due to phrenic nerve blockade. These patients are not ideal candidates for
increased opiate therapy for intraoperative and post-surgical pain as well due to further
depression of their respiratory function. To optimize their pain control as well as avoid any
respiratory-related morbidity and mortality, it is ideal to develop a technique which can
provide appropriate brachial plexus block at the interscalene level while completely avoiding
any local anesthetic spread to the phrenic nerve.

The study aims to examine the influence of out of plane interscalene approach to a brachial
plexus block on the effect of phrenic nerve blockade. Practitioner preference and
institutional norms often influence the in plane approach for the above-mentioned block. The
most common practice at our institution is the in plane approach to the brachial plexus
block.

Inclusion Criteria:

- Adult patients(18-85 years old)

- Scheduled for elective shoulder surgery who would benefit from a preoperative
interscalene approach to the brachial plexus block for intraoperative and
postoperative pain relief.

Exclusion Criteria:

- Patients with any distorted anatomy for whom the block cannot be performed accurately,
such as scars, surgical fixtures at the site, active infection, any open wound or
drains at the site.

- Patients who request benzodiazepine anxiolytics such as midazolam for premedication
before the procedure. Also patients who request narcotic medications as premedication
before the procedure

- Non-English and Non-Spanish speaking patients

- Inadequate or failed blocks and inadvertently intrathecal or intravascular injection
will be dropped from the study

- Incarcerated patients

- Expected heavy bleeding on multiple anticoagulants with markedly elevated PT (
Prothrombin time ), INR (International Normalized Ratio ), PTT ( Partial
Thromboplastin Time ) levels and markedly reduced platelet counts